• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 // RUN: %clang_cc1 -fsyntax-only -Wuninitialized -Wconditional-uninitialized -fsyntax-only -fblocks %s -verify
2 
3 typedef __typeof(sizeof(int)) size_t;
4 void *malloc(size_t);
5 
test1()6 int test1() {
7   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
8   return x; // expected-warning{{variable 'x' is uninitialized when used here}}
9 }
10 
test2()11 int test2() {
12   int x = 0;
13   return x; // no-warning
14 }
15 
test3()16 int test3() {
17   int x;
18   x = 0;
19   return x; // no-warning
20 }
21 
test4()22 int test4() {
23   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
24   ++x; // expected-warning{{variable 'x' is uninitialized when used here}}
25   return x;
26 }
27 
test5()28 int test5() {
29   int x, y; // expected-note{{initialize the variable 'y' to silence this warning}}
30   x = y; // expected-warning{{variable 'y' is uninitialized when used here}}
31   return x;
32 }
33 
test6()34 int test6() {
35   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
36   x += 2; // expected-warning{{variable 'x' is uninitialized when used here}}
37   return x;
38 }
39 
test7(int y)40 int test7(int y) {
41   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
42   if (y) // expected-warning{{variable 'x' is used uninitialized whenever 'if' condition is false}} \
43          // expected-note{{remove the 'if' if its condition is always true}}
44     x = 1;
45   return x; // expected-note{{uninitialized use occurs here}}
46 }
47 
test7b(int y)48 int test7b(int y) {
49   int x = x; // expected-note{{variable 'x' is declared here}}
50   if (y)
51     x = 1;
52   // Warn with "may be uninitialized" here (not "is sometimes uninitialized"),
53   // since the self-initialization is intended to suppress a -Wuninitialized
54   // warning.
55   return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
56 }
57 
test8(int y)58 int test8(int y) {
59   int x;
60   if (y)
61     x = 1;
62   else
63     x = 0;
64   return x;
65 }
66 
test9(int n)67 int test9(int n) {
68   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
69   for (unsigned i = 0 ; i < n; ++i) {
70     if (i == n - 1)
71       break;
72     x = 1;
73   }
74   return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
75 }
76 
test10(unsigned n)77 int test10(unsigned n) {
78   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
79   for (unsigned i = 0 ; i < n; ++i) {
80     x = 1;
81   }
82   return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
83 }
84 
test11(unsigned n)85 int test11(unsigned n) {
86   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
87   for (unsigned i = 0 ; i <= n; ++i) {
88     x = 1;
89   }
90   return x; // expected-warning{{variable 'x' may be uninitialized when used here}}
91 }
92 
test12(unsigned n)93 void test12(unsigned n) {
94   for (unsigned i ; n ; ++i) ; // expected-warning{{variable 'i' is uninitialized when used here}} expected-note{{initialize the variable 'i' to silence this warning}}
95 }
96 
test13()97 int test13() {
98   static int i;
99   return i; // no-warning
100 }
101 
102 // Simply don't crash on this test case.
test14()103 void test14() {
104   const char *p = 0;
105   for (;;) {}
106 }
107 
test15()108 void test15() {
109   int x = x; // no-warning: signals intended lack of initialization.
110 }
111 
test15b()112 int test15b() {
113   // Warn here with the self-init, since it does result in a use of
114   // an unintialized variable and this is the root cause.
115   int x = x; // expected-warning {{variable 'x' is uninitialized when used within its own initialization}}
116   return x;
117 }
118 
119 // Don't warn in the following example; shows dataflow confluence.
120 char *test16_aux();
test16()121 void test16() {
122   char *p = test16_aux();
123   for (unsigned i = 0 ; i < 100 ; i++)
124     p[i] = 'a'; // no-warning
125 }
126 
test17()127 void test17() {
128   // Don't warn multiple times about the same uninitialized variable
129   // along the same path.
130   int *x; // expected-note{{initialize the variable 'x' to silence this warning}}
131   *x = 1; // expected-warning{{variable 'x' is uninitialized when used here}}
132   *x = 1; // no-warning
133 }
134 
test18(int x,int y)135 int test18(int x, int y) {
136   int z;
137   if (x && y && (z = 1)) {
138     return z; // no-warning
139   }
140   return 0;
141 }
142 
143 int test19_aux1();
144 int test19_aux2();
145 int test19_aux3(int *x);
test19()146 int test19() {
147   int z;
148   if (test19_aux1() + test19_aux2() && test19_aux1() && test19_aux3(&z))
149     return z; // no-warning
150   return 0;
151 }
152 
test20()153 int test20() {
154   int z; // expected-note{{initialize the variable 'z' to silence this warning}}
155   if ((test19_aux1() + test19_aux2() && test19_aux1()) || test19_aux3(&z)) // expected-warning {{variable 'z' is used uninitialized whenever '||' condition is true}} expected-note {{remove the '||' if its condition is always false}}
156     return z; // expected-note {{uninitialized use occurs here}}
157   return 0;
158 }
159 
test21(int x,int y)160 int test21(int x, int y) {
161   int z; // expected-note{{initialize the variable 'z' to silence this warning}}
162   if ((x && y) || test19_aux3(&z) || test19_aux2()) // expected-warning {{variable 'z' is used uninitialized whenever '||' condition is true}} expected-note {{remove the '||' if its condition is always false}}
163     return z; // expected-note {{uninitialized use occurs here}}
164   return 0;
165 }
166 
test22()167 int test22() {
168   int z;
169   while (test19_aux1() + test19_aux2() && test19_aux1() && test19_aux3(&z))
170     return z; // no-warning
171   return 0;
172 }
173 
test23()174 int test23() {
175   int z;
176   for ( ; test19_aux1() + test19_aux2() && test19_aux1() && test19_aux3(&z) ; )
177     return z; // no-warning
178   return 0;
179 }
180 
181 // The basic uninitialized value analysis doesn't have enough path-sensitivity
182 // to catch initializations relying on control-dependencies spanning multiple
183 // conditionals.  This possibly can be handled by making the CFG itself
184 // represent such control-dependencies, but it is a niche case.
test24(int flag)185 int test24(int flag) {
186   unsigned val; // expected-note{{initialize the variable 'val' to silence this warning}}
187   if (flag)
188     val = 1;
189   if (!flag)
190     val = 1;
191   return val; // expected-warning{{variable 'val' may be uninitialized when used here}}
192 }
193 
test25()194 float test25() {
195   float x; // expected-note{{initialize the variable 'x' to silence this warning}}
196   return x; // expected-warning{{variable 'x' is uninitialized when used here}}
197 }
198 
199 typedef int MyInt;
test26()200 MyInt test26() {
201   MyInt x; // expected-note{{initialize the variable 'x' to silence this warning}}
202   return x; // expected-warning{{variable 'x' is uninitialized when used here}}
203 }
204 
205 // Test handling of sizeof().
test27()206 int test27() {
207   struct test_27 { int x; } *y;
208   return sizeof(y->x); // no-warning
209 }
210 
test28()211 int test28() {
212   int len; // expected-note{{initialize the variable 'len' to silence this warning}}
213   return sizeof(int[len]); // expected-warning{{variable 'len' is uninitialized when used here}}
214 }
215 
test29()216 void test29() {
217   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
218   (void) ^{ (void) x; }; // expected-warning{{variable 'x' is uninitialized when captured by block}}
219 }
220 
test30()221 void test30() {
222   static int x; // no-warning
223   (void) ^{ (void) x; };
224 }
225 
test31()226 void test31() {
227   __block int x; // no-warning
228   (void) ^{ (void) x; };
229 }
230 
231 int test32_x;
test32()232 void test32() {
233   (void) ^{ (void) test32_x; }; // no-warning
234 }
235 
test_33()236 void test_33() {
237   int x; // no-warning
238   (void) x;
239 }
240 
test_34()241 int test_34() {
242   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
243   (void) x;
244   return x; // expected-warning{{variable 'x' is uninitialized when used here}}
245 }
246 
247 // Test that this case doesn't crash.
test35(int x)248 void test35(int x) {
249   __block int y = 0;
250   ^{ y = (x == 0); }();
251 }
252 
253 // Test handling of indirect goto.
test36()254 void test36()
255 {
256   void **pc; // expected-note{{initialize the variable 'pc' to silence this warning}}
257   void *dummy[] = { &&L1, &&L2 };
258  L1:
259     goto *pc; // expected-warning{{variable 'pc' is uninitialized when used here}}
260  L2:
261     goto *pc;
262 }
263 
264 // Test && nested in ||.
265 int test37_a();
266 int test37_b();
test37()267 int test37()
268 {
269     int identifier;
270     if ((test37_a() && (identifier = 1)) ||
271         (test37_b() && (identifier = 2))) {
272         return identifier; // no-warning
273     }
274     return 0;
275 }
276 
277 // Test merging of path-specific dataflow values (without asserting).
test38(int r,int x,int y)278 int test38(int r, int x, int y)
279 {
280   int z;
281   return ((r < 0) || ((r == 0) && (x < y)));
282 }
283 
test39(int x)284 int test39(int x) {
285   int y; // expected-note{{initialize the variable 'y' to silence this warning}}
286   int z = x + y; // expected-warning {{variable 'y' is uninitialized when used here}}
287   return z;
288 }
289 
290 
test40(int x)291 int test40(int x) {
292   int y; // expected-note{{initialize the variable 'y' to silence this warning}}
293   return x ? 1 : y; // expected-warning {{variable 'y' is uninitialized when used here}}
294 }
295 
test41(int x)296 int test41(int x) {
297   int y; // expected-note{{initialize the variable 'y' to silence this warning}}
298   if (x) y = 1; // expected-warning{{variable 'y' is used uninitialized whenever 'if' condition is false}} \
299                 // expected-note{{remove the 'if' if its condition is always true}}
300   return y; // expected-note{{uninitialized use occurs here}}
301 }
302 
test42()303 void test42() {
304   int a;
305   a = 30; // no-warning
306 }
307 
308 void test43_aux(int x);
test43(int i)309 void test43(int i) {
310   int x; // expected-note{{initialize the variable 'x' to silence this warning}}
311   for (i = 0 ; i < 10; i++)
312     test43_aux(x++); // expected-warning {{variable 'x' is uninitialized when used here}}
313 }
314 
test44(int i)315 void test44(int i) {
316   int x = i;
317   int y; // expected-note{{initialize the variable 'y' to silence this warning}}
318   for (i = 0; i < 10; i++ ) {
319     test43_aux(x++); // no-warning
320     x += y; // expected-warning {{variable 'y' is uninitialized when used here}}
321   }
322 }
323 
test45(int j)324 int test45(int j) {
325   int x = 1, y = x + 1;
326   if (y) // no-warning
327     return x;
328   return y;
329 }
330 
test46()331 void test46()
332 {
333   int i; // expected-note{{initialize the variable 'i' to silence this warning}}
334   int j = i ? : 1; // expected-warning {{variable 'i' is uninitialized when used here}}
335 }
336 
test47(int * i)337 void *test47(int *i)
338 {
339   return i ? : 0; // no-warning
340 }
341 
test49(int * i)342 void *test49(int *i)
343 {
344   int a;
345   return &a ? : i; // no-warning
346 }
347 
test50()348 void test50()
349 {
350   char c[1 ? : 2]; // no-warning
351 }
352 
test51(void)353 int test51(void)
354 {
355     __block int a;
356     ^(void) {
357       a = 42;
358     }();
359     return a; // no-warning
360 }
361 
362 // FIXME: This is a false positive, but it tests logical operations in switch statements.
test52(int a,int b)363 int test52(int a, int b) {
364   int x;  // expected-note {{initialize the variable 'x' to silence this warning}}
365   switch (a || b) { // expected-warning {{switch condition has boolean value}}
366     case 0:
367       x = 1;
368       break;
369     case 1:
370       x = 2;
371       break;
372   }
373   return x; // expected-warning {{variable 'x' may be uninitialized when used here}}
374 }
375 
test53()376 void test53() {
377   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
378   int y = (x);  // expected-warning {{variable 'x' is uninitialized when used here}}
379 }
380 
381 // This CFG caused the uninitialized values warning to inf-loop.
382 extern int PR10379_g();
PR10379_f(int * len)383 void PR10379_f(int *len) {
384   int new_len; // expected-note{{initialize the variable 'new_len' to silence this warning}}
385   for (int i = 0; i < 42 && PR10379_g() == 0; i++) {
386     if (PR10379_g() == 1)
387       continue;
388     if (PR10379_g() == 2)
389       PR10379_f(&new_len);
390     else if (PR10379_g() == 3)
391       PR10379_f(&new_len);
392     *len += new_len; // expected-warning {{variable 'new_len' may be uninitialized when used here}}
393   }
394 }
395 
396 // Test that sizeof(VLA) doesn't trigger a warning.
test_vla_sizeof(int x)397 void test_vla_sizeof(int x) {
398   double (*memory)[2][x] = malloc(sizeof(*memory)); // no-warning
399 }
400 
401 // Test absurd case of deadcode + use of blocks.  This previously was a false positive
402 // due to an analysis bug.
test_block_and_dead_code()403 int test_block_and_dead_code() {
404   __block int x;
405   ^{ x = 1; }();
406   if (0)
407     return x;
408   return x; // no-warning
409 }
410 
411 // This previously triggered an infinite loop in the analysis.
PR11069(int a,int b)412 void PR11069(int a, int b) {
413   unsigned long flags;
414   for (;;) {
415     if (a && !b)
416       break;
417   }
418   for (;;) {
419     // This does not trigger a warning because it isn't a real use.
420     (void)(flags); // no-warning
421   }
422 }
423 
424 // Test uninitialized value used in loop condition.
rdar9432305(float * P)425 void rdar9432305(float *P) {
426   int i; // expected-note {{initialize the variable 'i' to silence this warning}}
427   for (; i < 10000; ++i) // expected-warning {{variable 'i' is uninitialized when used here}}
428     P[i] = 0.0f;
429 }
430 
431 // Test that fixits are not emitted inside macros.
432 #define UNINIT(T, x, y) T x; T y = x;
433 #define ASSIGN(T, x, y) T y = x;
test54()434 void test54() {
435   UNINIT(int, a, b);  // expected-warning {{variable 'a' is uninitialized when used here}} \
436                       // expected-note {{variable 'a' is declared here}}
437   int c;  // expected-note {{initialize the variable 'c' to silence this warning}}
438   ASSIGN(int, c, d);  // expected-warning {{variable 'c' is uninitialized when used here}}
439 }
440 
441 // Taking the address is fine
442 struct { struct { void *p; } a; } test55 = { { &test55.a }}; // no-warning
443 struct { struct { void *p; } a; } test56 = { { &(test56.a) }}; // no-warning
444 
uninit_in_loop()445 void uninit_in_loop() {
446   int produce(void);
447   void consume(int);
448   for (int n = 0; n < 100; ++n) {
449     int k; // expected-note {{initialize}}
450     consume(k); // expected-warning {{variable 'k' is uninitialized}}
451     k = produce();
452   }
453 }
454 
uninit_in_loop_goto()455 void uninit_in_loop_goto() {
456   int produce(void);
457   void consume(int);
458   for (int n = 0; n < 100; ++n) {
459     goto skip_decl;
460     int k; // expected-note {{initialize}}
461 skip_decl:
462     // FIXME: This should produce the 'is uninitialized' diagnostic, but we
463     // don't have enough information in the CFG to easily tell that the
464     // variable's scope has been left and re-entered.
465     consume(k); // expected-warning {{variable 'k' may be uninitialized}}
466     k = produce();
467   }
468 }
469 
470 typedef char jmp_buf[256];
471 extern int setjmp(jmp_buf env); // implicitly returns_twice
472 
473 void do_stuff_and_longjmp(jmp_buf env, int *result) __attribute__((noreturn));
474 
returns_twice()475 int returns_twice() {
476   int a; // expected-note {{initialize}}
477   if (!a) { // expected-warning {{variable 'a' is uninitialized}}
478     jmp_buf env;
479     int b;
480     if (setjmp(env) == 0) {
481       do_stuff_and_longjmp(env, &b);
482     } else {
483       a = b; // no warning
484     }
485   }
486   return a;
487 }
488 
compound_assign(int * arr,int n)489 int compound_assign(int *arr, int n) {
490   int sum; // expected-note {{initialize}}
491   for (int i = 0; i < n; ++i)
492     sum += arr[i]; // expected-warning {{variable 'sum' is uninitialized}}
493   return sum / n;
494 }
495 
compound_assign_2()496 int compound_assign_2() {
497   int x; // expected-note {{initialize}}
498   return x += 1; // expected-warning {{variable 'x' is uninitialized}}
499 }
500 
compound_assign_3()501 int compound_assign_3() {
502   int x; // expected-note {{initialize}}
503   x *= 0; // expected-warning {{variable 'x' is uninitialized}}
504   return x;
505 }
506 
self_init_in_cond(int * p)507 int self_init_in_cond(int *p) {
508   int n = ((p && (0 || 1)) && (n = *p)) ? n : -1; // ok
509   return n;
510 }
511 
512 void test_analyzer_noreturn_aux() __attribute__((analyzer_noreturn));
513 
test_analyzer_noreturn(int y)514 void test_analyzer_noreturn(int y) {
515   int x; // expected-note {{initialize the variable 'x' to silence this warning}}
516   if (y) {
517     test_analyzer_noreturn_aux();
518 	++x; // no-warning
519   }
520   else {
521 	++x; // expected-warning {{variable 'x' is uninitialized when used here}}
522   }
523 }
test_analyzer_noreturn_2(int y)524 void test_analyzer_noreturn_2(int y) {
525   int x;
526   if (y) {
527     test_analyzer_noreturn_aux();
528   }
529   else {
530 	x = 1;
531   }
532   ++x; // no-warning
533 }
534